1. Field
Example embodiments relate to methods and/or apparatuses for reducing noise in an image and/or an image processing apparatus using the same.
2. Description of the Related Art
Technology for manufacturing an image sensor that generates digital images with high resolution is advancing, and these advanced image sensors may be utilized in a camera module applied to a mobile apparatus such as a smartphone. As the resolution of the digital images increases, there is an increasing demand for a clear digital image. An image signal processor (ISP) semiconductor circuit, connected to an image sensor, may affect image quality. For example, the ISP semiconductor circuit may include a noise removal algorithm for reducing noise.
A noise removal algorithm that removes noises based on local means may allocate weights to pixel values pixel values by determining a similarity in the units of pixels. In contrast, a non-local means may allocate weight to pixel values by determining a similarity between local groups that consist of a plurality of pixels (a collection of pixels having a certain size of area with one pixel at a center, hereinafter, referred as a patch). Noise removal algorithm based on non-local means may produce crisp images compared to typical noise removal algorithms, and, therefore, may be employed in various fields in which digital images are used. The noise removal algorithm based on non-local means may also be employed for a depth image that is used to generate a three-dimensional (3D) image, as well as a general or medical image.